Furuno FR-1710 manual Collision Assessment by the Offset EBL

Range and bearing to cursor

0.55NM

15.0°R

Cursor Target

If relative motion is selected, it is also possible to read CPA (Closest Point of Approach) by using a VRM as shown in Figure 1-17(a). If the EBL passes through the sweep origin (own ship) as illustrated

	No. 2 EBL
	(dashed)
Bearing to		EBL
		45.5°R		No. 1 EBL
No. 1 EBL		314.0°R
Bearing to				(dotted)
No. 2 EBL			Active marker is
			circumscribed.

Figure 1-17(b), the target ship is on a collision course.

5.To return the EBL origin to the own ship position, press the [EBL OFFSET] key again.

Cursor

Figure 1-16 How to measure

bearing by EBL

1.20Collision Assessment by the Offset EBL

A

A1

No.1

EBL

EBL

140.0°R

No.1

VRM

VRM

3.85NM

The origin of the EBL can be placed any- where with the trackball to enable measure- ment of range and bearing between any targets. This function is also useful for as- sessment of the potential risk of collision.

To assess possibility of collision:

1.Press the [EBL ON] key to display or ac- tivate EBL No.1.

2.Place the cursor (+) on a target of inter- est (A in the illustrated example) by oper- ating the trackball.

3.Press the [EBL OFFSET] key, and the origin of the active EBL shifts to the cur- sor position. Press the [EBL OFFSET] key again to anchor the EBL origin.

4.After waiting for a few minutes (at least 3 minutes), operate the EBL rotary control until the EBL bisects the target at the new position (A’). The EBL readout shows the target ship’s course, which may be true or relative depending on the settings on the OTHER menu.

(a)Evaluating target ship’s course and CPA in relative motion mode

Cursor

A

A1	No.1
	EBL

EBL	VRM
118.2°R		0.00nm

(b) Target ship on collision course

Figure 1-17 How to assess risk of collision

1.21Measuring Range and Bearing Between Two Targets

1.Press the [EBL ON] key to activate the No. 1 EBL. Press the [EBL OFFSET] key, and place the origin of the No.1 EBL on a target of interest (target 1 in Figure 1-18) by operating the trackball.

2.Turn the EBL rotary control until the EBL passes through another target of interest (target 2 in Figure 1-18).

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